Mechanism of Aryldestannylation of Alkenylstannanes with Arylpalladium Complexes

芳基钯配合物对烯基锡烷的芳基脱锡烷基化反应机理

• 批准号: 02640413
• 负责人: KIKUKAWA Kiyoshi
• 金额: $ 1.28万
• 依托单位: Kinki University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1990
• 资助国家: 日本
• 起止时间: 1990 至 1991
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-02640413/
• 关键词: Alkenylstannanes; Organotins; Organopalladium; Homogeneous Catalyst; Transmetallation; C-C Coupling; Arylation; Electrophilic Substitution

Both ArPd(PPh_3)_2I and ArPd(PPh_3)_2BF_4 aryldestannylated PhCH=CHSnR_3 and Ph(R_3Sn)C=CH_2(R=Bu, Ph)to give PhCH=CHAr and Ph(Ar)C=CH_2, respectively. In the absence of strong neutral ligands such as PPh@_3, however, the counter anion of the palladum complexes showed drastic effect on the reaction profile. Reaction with PhCH=CHSnR_3, [ArPd]^+BF_4^- gave Ph(Ar)C=CH_2, whereas Ar-Pd-I gave PhCH=CHAr.In the presence of coordinatively strong ligands such as PPh_3 or I^-, arylpalladium complexes aryldestannylate alkenylstannanes via transmetallation-reductive elimination mechanism as following scheme.<<chemical formula>>In the absence of coordinatively strong ligands, the reaction with [Ar-Pd]^+BF_4^- proceeds through addition-elimination mechanism as following scheme.<<chemical formula>>In the palladium catalyzed C-C coupling of organic electrophiles with organometallics, organs-palladium species expect to be a key intermediate. Present results exemplify an important role of the ligands of organopalladium intermediates to design reaction pathway.

ArPd(PPh_3)_2I和ArPd(PPh_3)_2BF_4芳基脱氨化PhCH=CHSnR_3和Ph(R_3Sn)C=CH_2（R=Bu, Ph）得到PhCH=CHAr和Ph(Ar)C=CH_2。然而，在没有强中性配体如PPh@_3的情况下，钯配合物的反阴离子对反应谱表现出强烈的影响。与PhCH=CHSnR_3， [ArPd]^+BF_4^-反应得到Ph(Ar)C=CH_2，而Ar- pd - i反应得到PhCH=CHAr。在配位强配体如PPh_3或I^-存在的情况下，芳基钯配合物通过金属转化-还原消除机制使芳基癸烷与烯基锡烷相结合。<<化学式>>在没有配位强配体的情况下，与[Ar-Pd]^+BF_4^-的反应通过加减机制进行，如下图所示。在钯催化的有机亲电试剂与有机金属物的C-C偶联中，钯类有机物有望成为关键的中间体。这些结果说明了有机钯中间体配体在设计反应途径中的重要作用。